Should we be concerned about alcohol in bicycle crashes?

Narelle Haworth and Amy Schramm ICADTS 2010, Norway 22-26 August 2010

Outline • Background • Factors potentially affecting alcohol involvement • Data availability issues • Research setting • Analyses of crash data • Conclusions

Background • Alcohol in injured riders associated with – severity of outcome – not wearing helmets – riding at night – adult riders – hospital studies, rather than Police data • Driver alcohol sometimes more common than rider in bicycle crashes

Factors potentially increasing alcohol-related cycling crashes • Growth in size and diversity of cycling population – More adults – Cycling as the new golf – Hung-over commuters – Drink drivers who have lost licence • Balance and coordination demands of riding • Not illegal or perceived lack of enforcement

Factors potentially decreasing alcohol-related cycling crashes • Restricted overlap of riding and drinking patterns – by age group • half of hospitalised riders are children – by time of day • peaks 6-10 am and 2-6 pm for bicycle-MV crashes (Watson & Cameron, 2006) – by day of week • weekday pattern of bicycle crashes (Watson & Cameron, 2006) • Balance and coordination demands of riding – not ride if feeling affected?

• Factors affecting official data – less likely to report alcohol crash to Police?

Under-reporting of bicycle injuries • International research – 13% of bicycle crashes appear in official crash records in Norway (Veisten et al, 2007) – 11% in US data (Stutts et al, 1990) • Australian research – 3.5% of on-road cycling injuries reported to Police (Hendrie & Ryan, 1994) • Under-reporting greater for SV crashes and lower levels of severity • How accurate is hospital data?

Cycling in Queensland

Analysis of crash data • 7,293 Police-reported bicycle crashes Queensland 2003-2007 • Crashes on public roads only • Contributing factors for unit at fault only – “under the influence” – “over the prescribed BAC limit” – missing is a mixture of none and not known

Characteristics of Police-reported bicycle crashes • 94% bicycle-motor vehicle crashes, 4.5% single bicycle • Severity – fatality 1% – hospitalisation 35% – medical treatment 41% – minor injury 23% – non-injury <1% • Most crashes occurred 6-9 am and 3-6 pm • About 30% of reported crashes involved riders aged under 17 and so unlikely to be tested

% crashes where alcohol reported Severity Fatal Hospitalisation Medical treatment Minor injury Non-injury All severities All crashes 20.0 3.4 1.8 1.9 3.3 2.6 (7293)

% crashes where alcohol reported Severity Fatal Hospitalisation Medical treatment Minor injury Non-injury All severities Rider in single bicycle 20.0 12.9 5.6 Rider in bicycle-motor vehicle 17.0 2.9 1.9 Driver in bicycle-motor vehicle 26.7 2.7 1.5 6.8 - 9.5 (327) 2.5 0.0 2.6 (3058) 1.2 5.0 1.9 (3771)

Alcohol by rider characteristics Gender Male Female Age group 0-16 17-20 21-29 30-39 40-49 50-59 60+ Helmet Yes No Unknown Rider at fault 3.6% 1.8% 0.2% 4.2% 7.5% 7.9% 7.0% 7.9% 2.8% 2.2% 7.6% 8.2% Driver at fault 1.9% 1.8% 2.2% 1.1% 2.4% 1.7% 2.1% 1.6% 1.8% 1.7% 4.6% 5.6%

Alcohol by crash characteristics Day of week Weekday Weekend Lighting Day Dawn/dusk Dark Unknown Rider at fault 2.4% 4.0% 1.8% 4.6% 13.2% 6.7% Driver at fault 1.7% 3.5% 1.3% 1.7% 6.4% 0.0%

Summary • Alcohol more common in – fatal crashes – male riders – non-helmeted riders – weekend crashes – night crashes • Limitations – missing versus unknown – only riders and drivers at fault – no BAC levels – no off-road crashes

Conclusions • Increase in cycling and vulnerability of cyclists support need to examine alcohol in bicycle crashes • Driver alcohol contributes to alcohol in bicycle crashes • Alcohol contributes to injury by reducing helmet use • Improvements in data collection needed for firmer conclusions • Need to improve legislation, enforcement and testing

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International Council on Alcohol, Drugs and Traffic Safety Conference (ICADTS T2013) August 2013, Brisbane Convention and Exhibition Centre